Process of making colored nitrocellulose compositions



UNITED STATES PATENT OFFICE.

LESTER J. MALONE, OE ROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAK COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

PROCESS OF MAKING COLORED NITROCELLULOSE COMPOSITIONS.

No Drawing.

To all whom it may concern:

Be it known that I, LESTER J. MALONE, a citizen of the United States of America, residin at Rochester, in the county of Monroe and State of New York, have invented certain new and usefulImprovements in Processes of Making Colored Nitrocellulose Compositions, of which the following is a full, clear, and exact specification.

This invention relates to a process of making colored nitrocellulose compositions which can be advantageously used in the plastic arts, such, for instance, as film manufacture and varnish making. 4

One object of my invention is to provide a method of making colored compositions which will yield particularly uniform products. Another object of my invention is to provide a process in which relatively'inexpensive and easily manipulated water-soluble dyes may be employed. Other objects will hereinafter appear.

After nitrocellulose is taken from the nitrating acid, substantially all of the latter is removed by careful washing. Such washed nitrocellulose fibers are the preferredmaterial with which my process starts. immerse or otherwise treat themin an aqueous solution of dye, preferably -an acid dye, until they have assumed the proper tint. The strength of the dye bath maybe greatly varied, as will be understood by those skilled in this art. The dye solution penetrates very completely throughout all the fibers and the latter are, therefore, dyed with a high degree of uniformity. t

hen the fibers have taken up the desired amount of color, they are separated from the dye solution, the excess of the latter being washed out.

The colored nitrocellulose fibers are then dehydrated in themanner customary in this art. such as by treatment with butyl alcohol or fusel oil, and are then dissolved up into compositions or dopes. These colored fibers enter properly into all of the usual nitrocellulose compositions, particularly those employed in film manufacture or varnish making. By way of example, but without being in any way limited thereto, it is noted that these fibers can be used in the compositions described in United States Patents Nos. 1,342,602, Seel, June 8, 1920, and

Specification of Letters Patent.

Patented Dec. 6, 1921.

Application filed. April 20, 1921. Serial No. 463,092.

The color or dye passes into the composition or solution along with the fibers and, because of its uniform distribution through.- out all the fibers, it gives a uniform color to the dope with the minimum amount of mixing.

I find that the uniformity of dyeing the fibers, which in turn aids in the uniform coloring of the dope, is enhanced by the ability of the aqueous solution, of the dye to penetrate very rapidly and easily along the wet washed nitrocellulose fibers.

\Vhere it is desired that the finished compositions have a predetermined depth of color, I have found that my method is particularly useful. By immersing the fibers for a given time in a dye bath of given strength and temperature a definite tint results.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. The process of making a colored nitrocellulose composition, which comprises the steps of dying the nitrocellulose fibers and then dissolving said dyed fibers in a nitro- I cellulose solvent.

2. The process of making a colored nitrocellulose composition, which comprises the steps of coloring nitrocellulose fibers with an aqueous dye bath, removingthe surplus dye bath and then dissolving said colored fibers in a nitrocellulose solvent.

3. The process of making colored nitrocellulose compositions, which comprises the steps of treating wet nitrocellulose fibers with an aqueous dye bat-h until the fibers are colored, then washing away the excess of dye bath from the fibers, dehydrating said fibers and then dissolving the same in a nitrocellulose solvent.

4. The process of making acolored nitrocellulose composition, which comprises the steps of treating washed nitrocellulose fibers with an acid water-soluble dye bath until said fibers are colored, removing the surplus dye bath, dehydrating said fibers, and finally solvent.

Signed at Rochester, New York, tlns 11th day of April 1921.

LESTER J. MALONE.

1,370,922, Seel, Combs and Kemp, Mar. 8, I

dissolving the same in a nitrocellulose 

